This is an open label phase I study, to assess the safety of a novel malaria vaccine, AdCh63 CS, simian adenovirus encoding Plasmodium falciparum liver stage antigen, Circumsporozoite protein. All volunteers recruited will be healthy adults. They will be primed with various doses of AdCh63 CS administered intramuscularly. Some of the volunteers will receive a booster vaccination with MVA CS administered via intramuscular route. Safety data will be collected for each vaccination regimen. Secondary aim of this study will be to assess the immune responses generated by vaccination.

Inclusion Criteria

• Healthy adults aged 18 to 50 years
• Able and willing (in the Investigator"s opinion) to comply with all study requirements
• Willing to allow the investigators to discuss the volunteer"s medical history with their General Practitioner
• Women only: Must practice continuous effective contraception for the duration of the study
• Agreement to refrain from blood donation during the course of the study and for 6 months after the end of their involvement in the study.
• Written informed consent

Exclusion Criteria:

• History of clinical P. falciparum malaria
• Travel to a malaria endemic region during the study period or within the preceding six months with a significant risk of malaria exposure.
• Participation in another research study involving an investigational product in the 30 days preceding enrolment, or planned use during the study period.
• Prior receipt of an investigational malaria vaccine or any other investigational vaccine likely to impact on interpretation of the trial data.
• Administration of immunoglobulins and/or any blood products within the three months preceding the planned administration of the vaccine candidate.
• Any confirmed or suspected immunosuppressive or immunodeficient state, including HIV infection; asplenia; recurrent, severe infections and chronic (more than 14 days) immunosuppressant medication within the past 6 months (inhaled and topical steroids are allowed)
• Pregnancy, breast feeding or intention to become pregnant during the study
• History of allergic disease or reactions likely to be exacerbated by any component of the vaccine e.g. egg products, Kathon.
• History of clinically significant contact dermatitis.
• Any history of anaphylaxis post vaccination.
• History of cancer (except basal cell carcinoma of the skin and cervical carcinoma in situ).
• History of serious psychiatric condition that may affect participation in the study.
• Any other serious chronic illness requiring hospital specialist supervision.
• Suspected or known current alcohol abuse as defined by an alcohol intake of greater than 42 units every week.
• Suspected or known injecting drug abuse in the 5 years preceding enrolment.
• Seropositive for hepatitis B surface antigen (HBsAg).
• Seropositive for hepatitis C virus (antibodies to HCV).
• Any clinically significant abnormal finding on biochemistry or haematology blood tests, urinalysis or clinical examination.
• Any other significant disease, disorder or finding which may significantly increase the risk to the volunteer because of participation in the study, affect the ability of the volunteer to participate in the study or impair interpretation of the study data.